Having just returned from the National IPAC-Canada Conference and seeing the excitement that Prof. Didier Pittet can bring during his talk and book signings (as seen in the picture with my colleague Olivia Lattimore being more than just a little star struck), coming across an article that talks about hand size versus the amount of alcohol-based hand rub (ABHR) that needs to be used seemed like fate.
I’m not that big – 5 feet 5 inches if I stand with my very best posture and as one would assume, with a shorter frame I have fairly small hands (at least I think a ring size of 4.5 is pretty small). I’ve generally had more problems finding gloves that fit than ever thinking about whether the amount of hand sanitizer I use or is automatically dispensed is sufficient. It’s funny, we know when a glove is too big or too small and the problems that can occur with that, yet with hand sanitizers we all think one size fits all.
The article published in 2015 by Bellissimo-Rodrgues et al concludes that healthcare professionals need to consider the size of their hands when it comes to using ABHR products to ensure that adequate coverage, and therefore efficacy of the product, can be met. Their study investigated whether the volume of ABHR used by healthcare workers affects the residual bacterial concentration on their hands according to hand size, and found that bacterial reduction was significantly lower for large hands compared with small hands. This highlights the need for customizing the volume of alcohol-based hand rub for the most effective hand hygiene.
As the researchers acknowledged, "Over the past 20 years, ABHRs have become the preferential tool for hand hygiene in healthcare settings because of their high antimicrobial efficacy, tolerability, and accessibility. There is common sense and microbiologic evidence that the volume of ABHR used should be large enough to cover the whole surface area of both hands, but there is no consensus on how much is the minimum necessary, and whether healthcare worker hand size influences it."
For the study prior to each contamination procedure, participants washed their hands with 5mL of plain soap for 1 minute. Hands were then contaminated artificially by inserting them into the bacterial suspension 5 seconds, and held up to dry for 3 minutes. After the first contamination procedure, baseline bacterial recovery was obtained using the fingertip method. As a next step, participants washed their hands, re-contaminated them in the same way as before, and undertook a hand friction action with no ABHR and a second baseline recovery of bacteria was performed. Next the study participants applied the ABHR varying every 0.5 mL from 0.5 to 3 mL. The participants with large hands were investigated further with the application of 4, 5, and 6 mL of ABHR. The bacterial recovery step was repeated with each application.
The researchers found that overall there were no differences between the hand size categories and the average level of contamination of hands at baseline. As the volume of ABHR was increased, there was an associated decrease in the mean bacterial count and they also found that bacterial reduction was inversely and significantly associated with hand surface area.
The study without a doubt demonstrates a strong relationship between the reduction of bacterial count on hands and the amount of ABHR used for hand hygiene. The researchers concluded that it is a matter of concern that HCWs with large hands could not achieve a minimum of 2 log reduction of bacteria on their hands by the application of 3 mL of ABHR, the volume recommended by most manufacturers. That concern gets greater when we realize that the mean application volume of ABHR in clinical practice may be lower than 1 mL.
So? How big are your hands? If you have large hands, the next time you use hand sanitizer you may want to consider using 2 pumps!